The Swiss Competition Commission has launched an investigation into HSBC,
Barclays and five other banks

Swiss competition authorities are investigating HSBC, Barclays, Deutsche Bank and four other banks on suspicion of price fixing in the precious metals market.

The Swiss Competition Commission (COMCO) "has today opened an investigation against two Swiss banks, UBS and Julius Baer, as well as against the foreign financial institutions Deutsche Bank, HSBC, Barclays, Morgan Stanley and Mitsui," it said in a statement.

Previously several banks have referred to investigations into precious metals benchmarks.

In its second quarter financial results Barclays acknowledged it "has been providing information to the (US) Department of Justice and other authorities in connection with investigations into precious metals and precious metals-based financial instruments". The bank was fined £26m in May 2014 for failures in its controls that allowed a trader to try to manipulate the gold benchmark.

Deutsche Bank is also among those that has previously admitted it "has received requests for information from certain regulatory and law enforcement authorities who are investigating trading, and various other aspects of, precious metals. The bank is co-operating with these investigations."

The German bank is also among those facing class action lawsuits in the US over claims that its traders tried to manipulate gold and silver benchmarks.

However, industry insiders expect the precious metals probes in general, and the Swiss investigation in particular, to be much less costly than previous fines for foreign exchange and interest rate benchmark manipulation - if they do indeed result in fines or regulatory actions.

"All regulatory investigations are important, but there is no suggesting this will be anything like the Libor situation," said one banking source.

Another said: "The competition regulators generally cannot give big fines - it is not like the US' foreign exchange fines."